77 research outputs found
Local approximation by splines with displacement of nodes
We consider the problem of approximating a function defined on a uniform mesh by the method of local polynomial spline-approximation where the mesh of the nodes of the spline is chosen displaced relative to the mesh of the initial data. Conditions are established for the local form preservation by the spline of the initial data. We study the approximative properties of the method for the case of the simplest local approximation formula and find the optimal values of the displacement parameters. © 2013 Allerton Press, Inc
Dipole moments and conformations of benzyldiphenylphosphine oxides
The p-substituted benzyldiphenylphosphine oxides in solution have a conformation with a gauche orientation of the Csp3-Csp2 and P=O bonds. © 1982 Plenum Publishing Corporation
Water resources of the Sverdlovsk region
The quality of drinking water of the Sverdlovsk region does not meet the regulatory requirements, which is confirmed by studies of water quality in four districts of YekaterinburgКачество питьевой воды Свердловской области не отвечает нормативным требованиям, что подтверждается проведёнными исследованиями качества воды в четырех районах г. Екатеринбург
Role of coupling delay in oscillatory activity in autonomous networks of excitable neurons with dissipation
We study numerically the effects of time delay in networks of delay-coupled
excitable FitzHugh Nagumo systems with dissipation. The generation of periodic
self-sustained oscillations and its threshold are analyzed depending on the
dissipation of a single neuron, the delay time, and random initial conditions.
The peculiarities of spatiotemporal dynamics of time-delayed bidirectional
ring-structured FitzHugh-Nagumo neuronal systems are investigated in cases of
local and nonlocal coupling topology between the nodes, and a first-order
nonequilibrium phase transition to synchrony is established. It is shown that
the emergence of oscillatory activity in delay-coupled FitzHugh-Nagumo neurons
is observed for smaller values of the coupling strength as the dissipation
parameter decreases. This can provide the possibility of controlling the
spatiotemporal behavior of the considered neuronal networks. The observed
effects are quantified by plotting distributions of the maximal Lyapunov
exponent and the global order parameter in terms of delay and coupling
strength.Comment: 14 pages, 17 figure
Mechanical overstimulation causes acute injury and synapse loss followed by fast recovery in lateral-line neuromasts of larval zebrafish
Excess noise damages sensory hair cells, resulting in loss of synaptic connections with auditory nerves and, in some cases, hair-cell death. The cellular mechanisms underlying mechanically induced hair-cell damage and subsequent repair are not completely understood. Hair cells in neuromasts of larval zebrafish are structurally and functionally comparable to mammalian hair cells but undergo robust regeneration following ototoxic damage. We therefore developed a model for mechanically induced hair-cell damage in this highly tractable system. Free swimming larvae exposed to strong water wave stimulus for 2 hr displayed mechanical injury to neuromasts, including afferent neurite retraction, damaged hair bundles, and reduced mechanotransduction. Synapse loss was observed in apparently intact exposed neuromasts, and this loss was exacerbated by inhibiting glutamate uptake. Mechanical damage also elicited an inflammatory response and macrophage recruitment. Remarkably, neuromast hair-cell morphology and mechanotransduction recovered within hours following exposure, suggesting severely damaged neuromasts undergo repair. Our results indicate functional changes and synapse loss in mechanically damaged lateral-line neuromasts that share key features of damage observed in noise-exposed mammalian ear. Yet, unlike the mammalian ear, mechanical damage to neuromasts is rapidly reversible
Characterization of Leishmania spp. causing cutaneous leishmaniasis in Manaus, Amazonas, Brazil
In the State of Amazonas, American tegumentary leishmaniasis is endemic and presents a wide spectrum of clinical variability due to the large diversity of circulating species in the region. Isolates from patients in Manaus and its metropolitan region were characterized using monoclonal antibodies and isoenzymes belonging to four species of the parasite: Leishmania (Viannia) guyanensis, 73% (153/209); Leishmania (Viannia) braziliensis, 14% (30/209); Leishmania (Leishmania) amazonensis, 8% (17/209); and Leishmania (Viannia) naiffii, 4% (9/209). The most prevalent species was L. (V.) guyanensis. The principal finding of this study was the important quantity of infections involving more than one parasite species, representing 14% (29/209) of the total. The findings obtained in this work regarding the parasite are further highlighted by the fact that these isolates were obtained from clinical samples collected from single lesions
Лекарственная пневмопатия (организующаяся пневмония), ассоциированная с приемом месалазина
The article describes a clinical case of mesalazine-related lung disease in a patient treated for ulcerative colitis.Представлено клиническое наблюдение развития лекарственно-индуцированного поражения легких на фоне приема месалазина у пациента с язвенным колитом
Invasive aspergillosis in patients with COVID-19 in intensive care units: results of a multicenter study
Objective.
To study risk factors, clinical and radiological features and effectiveness of the treatment of invasive aspergillosis (IA) in adult patients with COVID-19 (COVID-IA) in intensive care units (ICU).
Materials and Methods.
A total of 60 patients with COVID-IA treated in ICU (median age 62 years, male – 58%) were included in this multicenter prospective study. The comparison group included 34 patients with COVID-IA outside the ICU (median age 62 years, male – 68%). ECMM/ISHAM 2020 criteria were used for diagnosis of CAPA, and EORTC/MSGERC 2020 criteria were used for evaluation of the treatment efficacy. A case-control study (one patient of the main group per two patients of the control group) was conducted to study risk factors for the development and features of CAPA. The control group included 120 adult COVID-19 patients without IA in the ICU, similar in demographic characteristics and background conditions. The median age of patients in the control group was 63 years, male – 67%.
Results.
64% of patients with COVID-IA stayed in the ICU. Risk factors for the COVID-IA development in the ICU: chronic obstructive pulmonary disease (OR = 3.538 [1.104–11.337], p = 0.02), and prolonged (> 10 days) lymphopenia (OR = 8.770 [4.177–18.415], p = 0.00001). The main location of COVID-IA in the ICU was lungs (98%). Typical clinical signs were fever (97%), cough (92%), severe respiratory failure (72%), ARDS (64%) and haemoptysis (23%). Typical CT features were areas of consolidation (97%), hydrothorax (63%), and foci of destruction (53%). The effective methods of laboratory diagnosis of COVID-IA were test for galactomannan in BAL (62%), culture (33%) and microscopy (22%) of BAL. The main causative agents of COVID-IA are A. fumigatus (61%), A. niger (26%) and A. flavus (4%). The overall 12-week survival rate of patients with COVID-IA in the ICU was 42%, negative predictive factors were severe respiratory failure (27.5% vs 81%, p = 0.003), ARDS (14% vs 69%, p = 0.001), mechanical ventilation (25% vs 60%, p = 0.01), and foci of destruction in the lung tissue on CT scan (23% vs 59%, p = 0.01).
Conclusions.
IA affects predominantly ICU patients with COVID-19 who have concomitant medical conditions, such as diabetes mellitus, hematological malignancies, cancer, and COPD. Risk factors for COVID-IA in ICU patients are prolonged lymphopenia and COPD. The majority of patients with COVID-IA have their lungs affected, but clinical signs of IA are non-specific (fever, cough, progressive respiratory failure). The overall 12-week survival in ICU patients with COVID-IA is low. Prognostic factors of poor outcome in adult ICU patients are severe respiratory failure, ARDS, mechanical ventilation as well as CT signs of lung tissue destruction
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